All pistons are made oval shaped (cammed) so that the sides have more clearance and that's to reduce drag between the pistons and bores which are the largest single source of friction in an engine.
I have little to no faith in coatings though I have seen a few reports that seem to suggest that they might make some small difference at first before they wear off.
Cams can be converted to needle rollers but again that's a fair amount of cost for not a lot of return. You can lighten the rocker arms and find titanium tappet nuts or adjusting screws. It all adds up eventually. Make sure the wheels spin freely without any drag in the bearings or brakes. That makes a difference.
You have time on your side, so a cam and or other updates can come as an upgrade in later years. You also have the opportunity to gather a few spare parts to work on and then swap them over.
Any weight saved improves acceleration and there's a lot of weight that can be removed if you start looking. Thinks like steel wheel spacers and bearing spacers can be replaced with aluminum parts. And they can be swapped in as you move along. A friend of mine drag races a GT750 Suzuki and each year he finds ways (weighs....) to trim off more weight. That way the bike just keeps improving and there's an ongoing development - long term development approach rather than a quickie let's get it done philosophy.
Look at Glass From the Past GFTP for fiberglass fenders at gerat prices.
We do additional work on our pistons to shorten and lighten them and even the tappet adjusting screws are machined. I had some broached with a small hex shape to make them hollow, saving a few fractions of a gram. We also change the internal breathing the same sort of idea that Suzuki finally invented for the later model GSXRs. I got that idea from Pops Yoshimura's tuning notes back in the sixties.
Get squish right is a great help and stop the cam chain from flopping around. Good crank mounted ignition is a boon if you can work it out for the street or at least get a GL1000 Dyna and cam mount it. It happens to be the same size backing plate as a CB160/175/200.
Grab a copy of Tuning For Speed which was first published when Pontius was a pilot
and is still relevant today. It covers the basics.